Hook lubrication system for sewing machines



Sept. 11, 1956 A. N. HALE ETAL HOOK LUBRICATION SYSTEM FOR SEWINGMACHINES 5 Sheets-Sheet 1 Filed Dec.

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HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed Dec. 29, 1955. 5Sheets-Sheet 2 imnu Magi/4 WW Y 684 681063 66 Sept. 11, 1956 A. N. HALEETAL 2,762,325

HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed Dec. 29, 1953 5Sheets-Sheet 5 Sept. 11, 1956 H E A 2,762,325

HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed D60. 29, 1953 5Sheets-Sheet 4 IFIG.I8

Sept. 11, 1956 A. N. HALE EIAL 2,762,325

HOOK LUBRICATION SYSTEM FOR SEWING MACHINES Filed Dec. 29, 1953 5Sheets-Sheet 5 HOOK LUBRTCATIGN SYSTEM FOR SEWING MACHINES Arthur N.Hale, Park Ridge, and Raymond T. Smith, McHenry, Ill., assignors toUnion Special Machine Company, Chicago, 111., a corporation of IllinoisApplication December 29, 1953, Serial No. 400,927 8 Claims. (Cl.112-256) This invention relates to sewing machines and more particularlyto sewing machines having a horizontal axis rotary hook. It is concernedparticularly with the lubrication of the hook raceway of such a machine.

In sewing machines of the type used industrially and intended for theproduction of lockstitches it has long been a problem to provideadequate lubrication of the raceway of the rotary hooks, withoutproviding such an excess of lubricant that the work being stitched willbe soiled by excess lubricant thrown from the revolving component of thehook onto the work or the threads which enter into the formation of theseam. The hooks in such machines are usually revolved at a high speed,e. g. 8,000 R. P. M. when stitches are to be formed at the rate of 4,000per minute. It is the desire to operate such machines at even a higherspeed and the hook is required to rotate at double the speed of stitchformation. At such high speeds it is difiicult to insure adequatelubrication, at all times, of the usual raceway provided between therotating and stationary components of the hook, without providing anexcessive amount of lubricant, at times, which will soil the work and bewasteful of the lubricant.

An object of the present invention has been to provide a hooklubrication system which will insure adequte lubrication of the hookraceway at all times and will avoid the delivery of an objectionableexcess of lubricant under any conditions encountered in the normal useof the machine.

In accordance with the foregoing object, an important feature of theinvention is the provision of a reservoir for the lubricant supplied tothe hook raceway which is capable of supplying lubricant by gravity tothe hook raceway. Means are provided, however, for readily cutting offsuch supply of lubricant by gravity to the raceway, this means beingassociated with the plug or other means associated with thelubricantreservoir for providing access to the latter to refill the same. Thearrangement is such that when the reservoir is to be refilled, theremoval of the plug or the like will automatically shut oi the deliveryof lubricant from the reservoir to the raceway. The arrangement is alsosuch that the plug may be adjusted, without removal thereof, to shut offdelivery of lubricant from the reservoir to the raceway, wheneverdesired, or to regulate the rate of supply of the lubricant to theraceway.

A more specific feature of the invention is the provision of meanswhereby the supply of lubricant from a reservoir to the hook raceway isnormally shut off but may be rendered effective to any extent desired byappropriate adjustment of the plug or means for rendering the reservoiraccessible for the introduction of a new quantity of lubricant thereto.

A further specific feature is the provision of the filling opening andthe plug or other closure means therefor in a member which serves tosecure the reservoir to the under surface of the work supporting memberof the machine fram Another important feature of the invention is theprovision of means within the body of the hook itself which will preventthe delivery of a slug of oil, which may have accumulated at some pointin the system, to the hook raceway. Such a slug of oil delivered to theraceway, for example upon the commencement of operation of the machineafter it has remained idle for a period of time, would give rise to thework soiling difiiculties which the present invention is intended toovercome.

Other objects, features and advantages of the invention will appear fromthe detailed description of an illus-v trative form of the inventionwhich will now be givenin conjunction with the accompanying drawings, inwhich: Fig. 1 is a longitudinal, vertical sectional view through alockstitch machine embodying the invention;

Fig. 2 is a bottom plan view of the machine with certain parts removedand others broken away and shown in section for clearer illustration;

Fig. 3 is an enlarged, vertical sectional view of a portion of the baseof the frame and a hook oil reservoir embodied in the machine, togetherwith associated parts;

Fig. 4 is an exploded perspective view of certain parts embodied in thehook oil reservoir assembly;

Fig. 5 is a view partly in plan and partly in horizontal section showingcertain details of the hook oil reservoir;

Fig. 6 is an enlarged longitudinal, sectional view through the rotaryhook and a portion of the hook shaft embodied in the machine;

Fig. 7 is a longitudinal, sectional view through the hook shaft of themachine;

Fig. 8 is an enlarged transverse, sectional view through the hook shaftof the machine along the line 8-8 of Fig. 7;

Fig. 9 is a plan view of a core pin or rod mounted within the hookshaft;

Fig. 10 is a view similar to Fig. 6 showing a modified assembly of therotating hook and the hook shaft;

Fig. 11 is a detail view, in perspective, showing a lubricant controlelement embodied in the assembly of Fig. 10; and

Fig. 12 is a detail view, in perspective, of a modified,

in the patent to Christensen and Rubel, No. 2,113,572,

granted April 12, 1938, and the patent to Rubel, No. 2,628,583, grantedFebruary 17, 1953.

Referring to Fig. 1, the machine is provided with a" main frame having awork supporting base portion 10, a

vertical standard 11, and a horizontally disposed overhanging arm 12which extends over the work supporting base and terminates in a needlehead 12a. Within the overhanging arm there is suitably journalled ashaft 13 which extends through the end wall of the vertical standard 11and carries at its outer end a combined hand wheel and pulley 14 throughwhich power may be supplied to the machine. Within the needle head theshaft 13 carries a crank 15 which is connected by means of a link 16with a needle bar 17 mounted for vertical reciprocation within theneedle head. This needle bar carries a needle 18 which is arranged forreciprocation between a position above the work support of the base to aposition in Which the eye of the needle is below the work support andarranged for cooperation with a rotary hook to be described. Gearing 19within the vertical standard serves to connect the shaft 13 with a shaft20 mounted in suitable bearings in the work supporting base. As shown inFig. 2, the shaft 20 is arranged to drive suitable work' 22 secured to ahook shaft 23. Gear 21 and pinion22 are such that for each revolution ofthe shaft 20, two

Patented Sept. 11, 1956;

revolutions will be imparted to the hook shaft 23. Shaft receives onerevolution for each revolution of the upper shaft 13. Carried by thehook shaft 23, at its left end, is a rotary hook indicated generally at24. This hook has a rotating component secured to shaft 23 andprovidedwith a needle loop seizing beak 26. Within thev rotary component of thehook there is mounted a bobbin basket 27 which is held against rotationby the action of a detent or retainer 28 having a projectionwhichcooperates. with a notch or recess 29 provided in the outer face of thebobbin basket. Extending circumferentially most of the way around theperiphery of the bobbin basket. is a rib 30 arranged to have bearingongagernent with a groove or raceway 31 provided in the inner surface ofthe cup like portion of the rotary con ponent of the'hook assembly.

As hereinabove' indicated, the present invention is concerned' with theprovision of means for supplying lubricant to the raceway 31 in amountssufficient to meet the requirements thereof without, however, bringingabout the delivery of excess lubricant at any time which may soil thework or the stitching threads. For the delivery of lubricant to theraceway, the hook body is provided with a small bore or passage 32 whichextends from the raceway to a radially extending bore or passage 33 thatcommunicates at its inner end with a substantially cylindrical pocket 34formed wihin the hub portion of the rotating component 25 of the hook.This pocket is formed betweenan enlarged head 35 at the end of the hookshaft, which fits tightly within the hub of the rotating component 25,and a closure disk 36 in the base of the hook body. The closure disk 36is provided with a small central aperture 37 for air venting purposes.its location is such that the lubricant will not be discharged throughit but air is admitted to the pocket 34- to prevent the deyeloprnent ofan air lock.

Hook shaft 23 has a bore, extending throughout its length, within whichis snugly fitted arod 38. The friction between the rod and the innerwall of the hook shaftis such that these parts will rotate together.Extending longitudinally of the rod 38 is a shallow and narrow groove 39adapted to deliver the desired amount of lubricant from a source ofsupply at the right end of they shaft (Fig. 7). Groove 39 is slightlydeeper at its right end, as indicated at 40, to facilitate introductionof lubricant into the bore of the shaft for delivery along the groove tothe pocket 34. Rod 38 is provided with a reduced stern portion 41 at itsright end which fits into an-opening 42 in the shaft which forms anextension of the axial bore in the shaft 19 but is of reduced diameter.Adequate clearance is provided between the stem 41- and the opening 42to permit the passage of at least the maximum amount of lubricantdesired for the hook raceway. At the extreme right end of the shaft acounterbore 43 is provided as an extension of the opening 42 to.facilitate the delivery of lubricant to the latter.

The right end of the hook shaft 23 is journalled in a bushing 44 (Figs.2 and 3) carried by a downwardly extending portion of the base it) ofthe frame. The end of the hook shaft extends into an enlarged opening44a in the bushing. To prevent the leakage of oil around the portion ofthe hook shaft which is within the bushing 44, a washer 45 mounted onthe shaft cooperates with the end of the bushing 44. A packing ring 46formed of rubber, felt, or other suitable compressible material, isprovided between the washer 45 and the inner end of the hub of thepinion 22. At the opposite end of the bushing 44 there is inserted atapered nipple element 47 having a shoulder which bears against a gasket48 the opposite face of which engages the adjacent end of the bushing44-. Nipple 47 is carried by a lubricant reservoir 49. the main body ofwhich is preferably die cast. The nipple may be incorporated in the mainbody in the. course of casting the latter or it may be inserted with atight fit afterwards. Reservoir 49 is secured to the under surface ofthe work supporting portion of the frame by means of a hollow, screwthreaded plug or sleeve 50. This has screw threaded engagement, asindicated at 51, with an opening in the top of the reservoir, and whenthe parts are assembled, as shown in Fig. 3, it serves to retain thereservoir firmly against the under face of the work support 10. A gasket52 is preferably provided between the head of the plug 50 and the uppersurface of the work support. An opening 53 in the latter, through whichthe plug extends, is of somewhat larger diameter than the outsidediameter of the plug to facilitate positioning of the reservoir so thatthe nipple 47 is maintained in proper relation to the right end of thehook shaft and serves to retain the gasket 48 against the end of thebushing 44. An upwardly extending projection 54 on the top of thereservoir, which also cooperates with the under face of the work support10, assists in retaining the reservoir in proper position.

A plug 55 having a screw threaded portion 56 which cooperates with screwthreads formed internally of the hollow plug 56 may be removed wheneverit is desired to refill the reservoir. As will be explained, this plugalso serves as a means for regulating the supply of lubricant from thereservoir to the hook raceway. At its right end (Fig. 3) the reservoiris closed by a plate 57 which is held against a gasket 58 by means of aseries of screws 59 (see also Figs. 4. and 5). A plug 60, carried by theplate 57, isprovided with an opening or recesslla which receivesthe endof a rod 61 the opposite end of which is tapered, as indicated at 62, tocooperate with a tapered opening extending through the nipple 47. Withinthe reservoir there is secured to the rod 61 a plate 63 having adownwardly extending projection 63a arranged for sliding engagement withthe bottom of the reservoir. A spring 64 surrounding the rod 61, andcompressed between the inner end of the plug 66 and the adjacent end 65of the plate 63, serves to urge the latter and the rod 61 toward theleft (Fig. 3). Thus, normally the tapered end 62 of the rod 61 is urgedinto a position to close off the passagethrough the nipple 47 whichcommunicates with the bore of the hook shaft. However, the rod 61 may beretracted against the action of the spring turning the plug 55 to causethe lower conical or tapered end 66 thereof to cooperate. with the wallof an opening 67 through the plate 63. Depending upon the extent towhich the plug 55 is turned in the direction to cause the tapered endthereof to move downwardly, the rod 61 Will be retracted to a greater orless extent, thus regulating the discharge.-

of lubricant from the reservoir. On removal of the plug- 55 to refillthev reservoir, the spring 64will become. automatically effective toclose oif the tapered opening through the nipple 47.

level of the lubricant within the reservoir. As shown in Figs. 3. and 5,the gauge for this purpose may simply. be a plug 68, formed of glass orLucite, or the like, which extends through the top of the reservoir intothe interior of the latter to a point adjacent its bottom. The lower endof this plug is provided with an inclined surface 68:: having a seriesof grooves or lines 68b at different levels. These and the level of thelubricant can be seen through the Lucite plug, which preferably extendsinto, or is positioned below a suitable opening through the work support10. ofthe frame. This gauge is of the. type. disclosed. in the'patent toSauer, No. 2,301,460, granted November 10, 1942.

To facilitate the insertion-of the rod 38 in the bore of the. hook shaft23 and its removal from the bore, the left end of the rod is providedwith a screw threaded opening 69. adapted to receive the stem of asuitable tool having a screw threaded end. The left end of the bore inthe hook shaft is preferably flared outwardly, as indicated at 70in Fig.7, to facilitate the proper flow of the lubricant toward the peripheryof the pocket 34 as the hook and hook shaft are rotated.

The supply of lubricant to the hook raceway from the reservoir 49 iseffected partially by gravity and partially by a slight pumping actioncreated by the construction and arrangement of the several parts. Whenthe machine 1s idle, and particularly if the reservoir 49 is relativelyfull at this time, it is desirable to close off the passage through thenipple 47 to prevent the delivery by gravity of further lubricant fromthe reservoir to the bore of the hook shaft. This may be accomplishedsimply by backing off the plug 55 to an extent suificient to permit thespring 64 to urge the rod 61 into the closing position.

Referring now to Figs. 10, 11 and 12, there is shown a slightmodification of the hook and hook shaft assembly which achieves anadditional purpose. In this modified arrangement the parts aresubstantially the same as shown in Fig. 6 and bear similar referencenumerals with the addition of an a. The difference between the twoarrangements is the provision, in the Fig. 10 embodiment, of an annularelement 71 within the pocket 34a in the hub of the rotating component ofthe hook. This annular member 71 is formed of felt or similar porousmaterial which permits the passage of lubricant through the same intothe channel 33a but prevents the delivery of a large slug of oil fromthe pocket 34a into the channel 33a. It has been found that without theprovision of a member of this character a certain amount of lubricantsometimes accumulates in the bore of the hook shaft and drains or isotherwise delivered into the pocket in the hook body. This may occur,for example, if the operator fails to turn the plug 55 to cause closingof the passage through the nipple 47 when the machine is left idle for atime. When it does occur and the machine is started up, after an idleperiod, a slug of oil will be thrown through the passages 33 and 32 tothe hook raceway with consequent soiling of the work or the stitchingthreads.

In lieu of the annular element 71 there may be inserted in the pocket34a of the hook body a disklike member 72 (Fig. 12) formed of similarporous material. If such a disklike member is employed it should havesufncient porosity to permit the passage of enough air through theopening 37a in the base of the hook body to prevent the system frombecoming air locked.

While an illustrative form of the invention has been described inconsiderable detail and certain variations have been suggested, it willbe understood that other changes may be made in the construction andarrangement of the several parts without departing from the generalprinciples and scope of the invention.

What is claimed is:

1. In a lock stitch sewing machine having a base with a work supportingsurface and a horizontally disposed hook shaft journaled in said base, ahook mounted on said shaft, said hook having a rotary component and astationary component, one of said components having a rib thereon andthe other component having a raceway for said rib, means for lubricatingsaid raceway which comprises a reservoir beneath said work supportingsurface adapted to retain lubricant at a level above the axis of saidhook shaft, said hook shaft having an axially extending bore arranged toreceive lubricant from said reservoir and deliver the same to saidraceway, said reservoir having a filling opening accessible through saidwork supporting surface, removable means for closing said fillingopening, and means rendered effective by removal of said removable meansfor preventing the delivery of lubricant from said reservoir to the boreof said hook shaft.

2. In a lock stitch sewing machine having a base with a work supportingsurface, a horizontally disposed hook shaft journaled in said base, ahook mounted on said shaft, said hook having a rotary component and astationary component, one of said components having a rib thereon andthe other component having a raceway for said rib, means for lubricatingsaid raceway which comprises a reservoir beneath said work supportingsurface adapted to retain lubricant at a level above the axis of of thehook shaft upon adjustment of said removable means.

3. In a lock stitch sewing machine having a horizontally disposed hookshaft, a hook mounted thereon, said hook having a rotary component and astationary component, one of said components having arib thereon and theother component having a raceway for said rib, means for lubricatingsaid raceway which comprises a reservoir adapted to retain lubricant ata level above the axis of said hook shaft, said hook shaft having anaxially extend ing bore throughout the length of said shaft arranged toreceive lubricant at one end thereof from said reservoir and deliver thesame to said raceway, said reservoir having a filling opening, removablemeans for closing said filling opening but adapted upon removal toenable filling of said reservoir, said removable means being adjustableto different closing positions in relation to said filling opening, andmeans controlled by said removable means in accordance with theadjustment thereof for regulating the delivery of lubricant from saidreservoir to the bore of the hook shaft, said means controlled by saidremovable means serving automatically to prevent delivery of lubricantfrom said reservoir to said bore upon removal of said removable means.

4. In a lock stitch sewing machine having a base with a work supportingsurface, a horizontally disposed hook shaft journaled in said base, ahook mounted on said shaft, said hook having a rotary component and astationary component, one of said components having a rib thereon andthe other component having a raceway for said rib, means for lubricatingsaid raceway which comprises a reservoir beneath said work supportingsurface adapted to retain lubricant at a level above the axis of saidhook shaft, said hook shaft having an axially extending'bore arranged toreceive lubricant from said reservoir and deliver the same to saidraceway, said reservoir having an outlet communicating with said bore ofthe hook shaft, a valve in said outlet adapted to close the same, saidreservoir having a filling opening remote from said outlet andaccessible through said work supporting surface, a removable closure forsaid filling opening, said closure being shiftable to different closingpositions in relation to said filling opening, and means controlled bysaid closure for closing said valve upon removal of said closure and foradjusting said valve to regulate the discharge of lubricant through saidoutlet upon shifting of said closure to said different closingpositions.

5. In a lock stitch sewing machine having a horizontally disposed hookshaft, a hook mounted thereon, said hook having a rotary component and astationary component, one of said components having a rib thereon andthe other component having a raceway for said rib, means for lubricatingsaid raceway which comprises a reservoir adapted to retain lubricant ata level above the axis of said hook shaft, said hook shaft having anaxially extending bore throughout its length arranged to receivelubricant from said reservoir and deliver the same to said raceway, saidreservoir having outlet means provided with a horizontally directedorifice communicating with said bore at one end of the hook shaft, aspring urged rod having a tapered end cooperating with said orifice andnormally urged into a closing position in relation thereto, saidreservoir having a vertically directed filling opening remote from saidorifice, and a removable closure for areas-2s 7- said filling openingcooperating with. said rod to shift the. same, out of said closingposition,

6. In. a lock stitch sewing machine having-a horizontally disposed hookshaft, a hook mounted thereon, said hook having a rotary component and astationary component, one of said components having a rib thereon andthe other component having a raceway for said rib, means for lubricatingsaid raceway which comprises a reservoir adapted to retain lubricant ata level above the axis of said hook shaft, said hook shaft having anaxially extending bore arranged to receive lubricant from said reservoirand deliver the same to said raceway, said reservoir having outlet meansprovided with an orifice communicatingwith said bore of the hook shaft,a spring urged rod having a tapered end cooperating with said orificeand normally urged into a closing position in relation. thereto, said.reservoir having a filling opening, and a. removable closure for saidfilling opening cooperating with said rod to shift the same out of saidclosing position, said closure being adjustable to different positionsin which it closes said filling opening, said rod being shifted todifferentextents to regulate the discharge of lubricant through saidorifice upon adjustment of said closure to said different positions.

7. In a lock stitch sewing machine having a hori: zontally disposed hookshaft having an axially extending bore therein, a hook mounted thereon,said hook having a rotary component and a stationary component, one ofsaid components havinga rib thereon and the other component having araceway for said rib, means for lubrieating said raceway which comprisesmeans in said rotary component providing a lubricant receiving pocketcommunicating with the bore in said shaft and a passage therefrom forthe delivery of lubricant to said raceway, said pocket being of largerdiameter than said bore, said rotary component having an air passagecommunicating, with said pocket adjacent the center thereof, a circularporous element in said pocket having an axial dimension less than itsdiameter extending over the inlet to said lubricant delivery passage,said porous element being'adapted to enable the relatively freepassage-of air therethrough from aid air pa sage, a res rv ir.- ad p ore inlubrican at a level above the axis of said hook shaft, said: hookshaft having, an axially, extending bore arranged, to receiye lubricant,from said, reservoir and deliver the same tov said pocket, said,reservoir. having a filling opening,

removable means. for. closing said filling opening, andmeans renderedeffective by removal of said removable means for preventing the deliveryof lubricant from. said reservoir: to the bore ofsaid hook shaft.

8. In a lock stitch sewing machine having a horizontally disposed hookshaft having an axially extendingbore therein, a hook mounted thereon,said hook having a rotary component anda stationary component, oneofsaid'componentshaving a rib thereon and the other cornponent' having a.raceway for said rib, means for lubrieating said raceway which comprisesmeans in said rotary component providing a substantially cylindricallubricantreceiving pocket therein in axial alignment withsaid shaft,said pocket, being of; larger diameter than said bore, a passageextending from. said pocket to said raceway for delivery of lubricant tothe latter, an annular member formed of porous material extending aroundthe wall of said pocket and over the inlet to said passage, said rotarycomponent having an opening. therein for the delivery of v air tosubstantially the center of said annular member,

References li tedinrthe file of this patent UNITED STATES PATENTS1,745,216 Horger V f n Ian, 28, 1930 2,098,904 Waterman Nov. 9,, 19372,385,288" Le Vesconte et a1. Sept. 18', 1945 2,395,653 Attwood' Eeb. 26, 1 946 2,628,583 .Rubel' p Feb. 17, 1953

